Beaches are being polluted more and more frequently by hydrocarbon waste, either following accidents when transporting oil cargoes or after tankers have cleaned out their tanks at sea. Environmental constraints make it necessary after accidental pollution to clean contaminated soil as quickly and as effectively as possible. Until now, sand has merely been riddled, thus removing pollution only above a certain size. The cleaning operations performed on beaches turn out to be unsatisfactory concerning the quality of the sand once it has been cleaned.
Hydrocarbon pollution can also take place on land. Thus, there are many sites that have been polluted, either by leaks from storage tanks or from pipes for conveying oil such as pipelines, or indeed from industrial installations.
One of the solutions that has been implemented in recent years consists in allowing the hydrocarbons to degrade in contact with the sea and the sun. Another solution consists in removing the contaminated sand, and then storing it or incinerating it. Those solutions are unsatisfactory concerning requirements not to bury waste other than ultimate waste that cannot be recycled.
Other solutions have been used more recently, involving a variety of solvents or absorbents. Those solutions are difficult and expensive to implement and run the risk of solvents migrating into the environment, or else they require incineration for final treatment of the absorbents.
WO 98/37991 discloses methods implementing oxidizing chemical agents for oxidizing radicals leading to the hydrocarbons being oxidized. Nevertheless, that type of oxidation reaction needs to be implemented in an acid medium and at high temperature (70° C. to 90° C.) in a series of closed reactors, with products and reagents being circulated by pumps. In particular, the hydroxyl radicals formed by the chemical mechanism of radical oxidation are removed by dedicated installations. Those installations cannot be transported and are not easily set up on polluted sites or in the vicinity thereof, i.e. where the polluted soil for treatment is to be found. Furthermore, given the installations required and their operating conditions, treatment costs are high. Finally, the treatment is not entirely effective, with said patent stating that best results are obtained at 85° C. enabling no more than 78.6% of the hydrocarbons to be eliminated.
Patents GB 2 010 798 and EP 071 50 751 describe methods in which effluent sludge or sand contaminated by infectious germs is treated with hydrogen peroxide for bactericidal purposes in order to deodorize and/or disinfect the treated sludge or sand, given the bactericidal properties of hydrogen peroxide.